Multi-spray device

ABSTRACT

A METHOD OF DISPERSING A LIQUID IN A MULTIPLICITY OF FINE MIST SPACED PATTERNS IS DISCLOSED. THE DEVICE CONSISTS OF AN INCLINED TROUGH HAVING A SERIES OF SUBTANTIALLY INCLINED BULBOUS PROTRUSIONS OVER WHICH LIQUID IS DIRECTED. AN ORIFICE IS LOCATED AT THE APEX OF EACH PROTRUSION THROUGH WHICH FLUID UNDER PRESSURE PASSES. A BLAST OF GASEOUS FLUID, FOR EXAMPLE AIR, IS DIRECTED THROUGH THE APERTURES THEREBY ATOMIZING THE FILM OF LIQUID PASSING OVER THE HOLES. BY INCLINING THE TROUGH, LIQUID NOT DISPRESED BU THE UPPERMOST BULBOUS PROTRUSION IS COLLECTED AND DIRECTED BY MEANS OF CONTOURED CHANNELS TO THE NEXT DOME UNDER GRAVITY FOR SUBSEQUENT ATOMIZATION THEREBY. THE UNUSED LIQUID IS THEN COLLECTED AND CIRCULATED BACK TO THE LIQUID SUPPLY TANK AND THENCE INTO A WEIR AT THE TOP OF THE TROUGH, THUS COMPLETING THE CYCLE. THE DEVICE THEREOF PROVIDES A MULTIPLE SPRAY ATOMIZING UNIT FROM ONE SOURCE OF LIQUID SUPPLY.

Sept. 20, 1971 p SUTTON 3,606,159

MULTI-SPRAY DEVICE Filed July 7,- 1969 2 Sheets-Sheet 1 28 Flaz "w 35 IN VIZNTOR.

GEORGE R SUTTON .fLLi

BY in; X 77m A T TORNE Y Sept. 20, 19 75 G. P. suT'roN MULTI-SPRAYDEVICE 2 Sheets-Sheet 2 Filed July '7, 1969 INI/IENTOR. GEORGE P. SUTTONflu. s. 7

A TTORNE Y 3,606,159 MULTI-SPRAY DEVICE George P. Sutton, Encino,Calif., assignor to North American Rockwell Corporation Filed July 7,1969, Ser. No. 839,270 Int. Cl. Bb 7/08 US. Cl. 239-127 Claims ABSTRACTOF THE DISCLOSURE A method of dispersing a liquid in a multiplicity offine mist spaced patterns is disclosed. The device consists of aninclined trough having a series of substantially inclined bulbousprotrusions over which liquid is directed. An orifice is located at theapex of each protrusion through which fluid under pressure passes. Ablast of gaseous fluid, for example air, is directed through theapertures thereby atomizing the film of liquid passing over the holes.By inclining the trough, liquid not dispersed by the uppermost bulbousprotrusion is collected and directed by means of contoured channels tothe next dome under gravity for subsequent atomization thereby. Theunused liquid is then collected and circulated back to the liquid supplytank and thence into a weir at the top of the trough, thus completingthe cycle. The device therefore provides a multiple spray atomizing unitfrom one source of liquid supply.

BACKGROUND OF THE INVENTION Atomization of a liquid to produce a finemist or fog is accomplished in the prior art in a number of ways.Notably, four patents issued to R. S. Babington et al., US. Patent Nos.3,421,692; 3,421,699; 3,425,058; and 3,425,059, all disclose a means toproduce a fog-like mist dispersing the liquid in extremely smallparticles of 5 microns or less.

The Babington et al. patents basically comprise passing a bulbous orcurved surface which causes the liquid to film out or stretch if theliquid is applied to a surface which has adhesive properties. Bystretching the film of liquid over a curved surface and passing the filmover a small aperture near the apex of the curved surface and bydirecting a jet of gas or air under pressure through the aperture, thefilm of liquid is stretched to the point of rupture thereby atomizingthe liquid into minuscule particles. The liquid atomization principlepatented by Babington et al. can be utilized in a number of differentareas of technology. A few examples include the following: humidifiers,gas cleaners for industry and fuel burners for both commercial anddomestic applications.

The devices depicted in the foregoing patents however are limited to asingle spray unit.

Therefore, it is an object of this invention to provide an improvementover the prior art in that a method is disclosed wherein multiple sprayfunctions are provided from a single liquid source.

More particularly, it is an object of this invention to disclose asimplified method for providing multiple spray patterns from a singlesource of liquid utilizing, for example, a preformed stamped metal plateserving the multiple function of channeling liquid toward the bulbousinjector elements on one side While the other side serves as an airchamber wherein air is directed to the elements having aperturestherein.

SUMMARY OF THE INVENTION Briefly, in accordance with the objects of thisinvention the multi-spray device is basically a preshaped inclinedtrough. In both the oil burner and the gas cleaning ap- United StatesPatent 3,606,159 Patented Sept. 20, 1971 plication the tilted troughcan, for example, be a stamped plate having a depression or weir at theuppermost end designed to receive liquid from a supply source. Theinboard lip of the weir feeds into a shaped channel which directs bygravitational pull, the liquid toward an upwardly extending roundedprotrusion. The liquid spreads over the bulbous dome in a thin film. Anorifice in the protrusion is located at the apex through which a gas(for example, air) is directed under pressure to rupture the filmpassing thereover. Liquid which escapes atomization by the protrusionlocated nearest the weir is collected downstream of the dome bycontoured channels and is directed towards the next protrusion whereinthe atomizing operation is repeated. Any number of upwardly extendingdomes either inline, offset or any other repetitive pattern can beformed into a plate and liquid can be directerd over the domes bychanneling between the protrusions as long as the plate is inclined ortilted to take advantage of gravitational forces. A collection bin orcatch basin is located at the lowermost edge of the plate to collect theunatomized liquid. The liquid is then recirculated back to the supplysource wherein the atomizing process is repeated. Any number ofapertures can be located in the domes and they can be in a variety ofshapes. The bottom of the plate serves as a manifold to direct the airunder pressure through the apertures in the domes. In the oil burnerapplication the atomizing plate may have a series of holes separate fromthe air manifolds and domes acting as feed holes for admitting a supplemental air supply to enhance oxidation or burning of the atomizedfuel oil above the plate.

An advantage over the prior art is realized in that the inclined dimpledand apertured plate provides a means for multiple atomization of aliquid from a single liquid supply source thereby simplifying andgreatly expanding the capacity of an oil burning or gas scrubbingoperation while taking advantage of the superior liquid atomizationprocess disclosed by the Babington et al. patents.

DESCRIPTION OF THE DRAWINGS The above noted objects and furtheradvantages of the present invention will be more fully understood uponthe study of the following detailed description in conjunction with thedetailed drawings in which:

FIG. 1 is a semi-schematic view of the multi-spray device as utilized inthe oil burner application;

FIG. 2 is a perspective view of one embodiment of the invention;

FIG. 3 is a fragmentary perspective view of still another embodiment ofthe invention;

FIG. 4 is a schematic view of the invention as utilized in the gascleaning field;

FIG. 5 is a perspective view of an embodiment of the invention whereinmultiple slots are utilized in each protrusion;

FIG. 6 is a top view taken along lines 6-6 of FIG. 5;

FIG. 7 is a front view of yet another embodiment of the inventionwherein the plate is oriented vertically, and;

FIG. 8 is a side view taken along lines 88 of FIG. 7.

Referring now to FIG. 1, the basic system 10 consists of a liquid supplytank 12, an atomizing trough 14, a liquid circulating system 16including pump 18 and a gas supply source 20.

In the oil burner application, fuel oil from supply tank 12 slowly flowsinto a depression or catch basin upstream of the weir 24 and the fluidspills over the weirs edge 26. The oil descends gravitationally downchannel 28 and over a bulbous protrusion or dome 30. Each of theupwardly extending domes 30, 33 and 35 has at least one aperture 32through the dome, located near the apex thereof. The oil is stretchedover the dome containing the aperture in part by means of surfacetension forces. The blower 20 supplies a gaseous fluid (air) underpressure down conduit 22 into chamber 23. Since the pressure in chamber23 is higher than the ambient pressure around the trough 14, the fluidescapes through the apertures 32 in the domes. Preferably, the pressurewithin chamber 23 is 4 to 10 p.s.i. above atmospheric pressure while 8p.s.i.g. would be optimum. When this happens, the surface tension of thefuel oil across the aperture 32 is ruptured causing the oil to atomizeinto a mist or fog 36 above the trough 14. The mixture 36 is thenignited above trough 14 in an oil burner housing (not shown). The fueloil that escapes atomization by the uppermost dome 30 is collected inbasin 29 down-stream of the dome 30 and directed via channel 28 to dome33 Where the atomization process previously described is repeated. Theremaining unburned oil finally reaches catch basin 34 wherein it emptiesinto conduit 16 and is pumped back to the liquid supply tank 12 by pump18.

The inclination of the device as illustrated in FIGS. 1 through 6 can bevery small, say, typically 2 to 8 degrees. In extreme cases theinclination may be as high as 12 degrees. Open channel steady flowtheory indicates a velocity of channel flow of 4 inches/sec. for degreesof inclination. A near horizontal position of the trough, in the oilburning application, would lend itself to easy conversion from theconventional state of the art oil burners, to the device of the presentinvention. The trough can be vertical or at any other inclination andstill operate as disclosed; however, slightly different designprovisions are needed for collecting and redirecting the excess liquidflow, namely, a closed funnel type collector instead of a simple openchannel collector (number 28, FIGS. 1 and 2) as indicated and describedin detial With reference to FIGS. 7 and 8.

Referring now to FIG. 2, the trough 14 can be, for example, made up oftwo stamped metal plates comprising an outer half cylindrical shell 15with an inner intricately formed plate 17 attached theerto. The innerplate 17 defines the weir 26, flow channel 28, upwardly extending domes30, 33 and 35 and catch basin 34. The ends 19 and 21 of shell 15 provideliquid tight walls for basin 24 and catch basin 34 at opposite ends oftrough 14. The cavity or fluid chamber 23 (FIG. 1) is defined by theinside walls of shell 15, end plates 19, 21 (FIG. 2) and the bottom ofstamped plate 17. Each of the domes have at least one aperture 32 nearthe top of the protrusion so that fluid under pressure can escapetherethrough. The aperture could be an elongated slot in the dome; infact, the aperture is preferably an elongated slot with its long axis 90to the flow of the liquid. Typical aperture dimensions (32) are slots.003 to .005 inch wide and 0.100 to 0.200 inch long. Obviously, anynumber of dome-like protrusions or dimples could be oriented on aninclined plate as seen in the fragmentary view of FIG. 3 and more thanone plate could be utilized (not shown) in any suitable arrangementprovided they are inclined to gravitationally flow liquid down the plateand over the protrusions.

In the oil burner application (FIG. 1) wherein fuel oil is burning at arate of l to 2 gallons/hour, the flow into a basin 24, would typicallybe at the rate of 5 to 12 gallons per hour and the trough is at aninclined angle of 3 to 8 degrees, the pressure in cavity 23 shouldtypically be between 5 to psi. above atmospheric pressure to providegood atomization above the protruding domes. Fuel burning rate from 0.3to gallons per hour could be attained with a single bulbous slot.

Plate 40 (FIG. 3) has multiple protrusions 42 extending from the plate.Each of these domes has at least one aperture 44 through the domes andthere can be a series of channels 46 connecting each dome. The apertures43 act as supplemental air holes to enhance oxidation or burning of theatomized fuel oil. The angle of inclination of plate 40 would dependupon the rate of flow 4 of the liquid to be atomized, the number ofupwardly extending protrusions, the viscosity of the liquid, plateadhesion properties, velocity of the gas flow through the apertures 44,etc.

An atomization plate of the fragmented configuration partially shown inFIG. 3 could be utilized in the gas scrubbing operation minus thesupplemental air holes 43 shown schematically in FIG. 4.

Scrubbers are used to remove solid and certain types of liquid andgaseous impurities from exhaust gas streams. They are used in many powerstation exhaust stacks, chemical mining, metallurgical and agriculturalprocesses wherein it is desirable indeed, imperative that the variousirritants and toxic exhaust properties be removed.

Turning now to the gas cleaning apparatus of FIG. 4, the scrubbergenerally designated as 60 comprises a liquid supply tank 62 which feedsliquid into a weir 63, the weir subsequently spills liquid onto thedimpled plate 64. The liquid not subjected to atomization eventuallyreaches catch basin 66. The liquid is recirculated back to tank 62 byconduit 68 and pump 70. Contaminated gas 72 under a slight pressure (4or 5 p.s.i. above atmospheric pressure) is directed through apertures 75in the domes 74 of plate 64, thereby rupturing the surface tension ofthe liquid. In the gas cleaning apparatus 60 it is preferable to havemore than one slot (75) in each protrusion as shown in FIGS. 5 and 6.The liquid can be, for example, water, and the water passing overapertures 74 is atomized by the contaminated gas above the dimpledscrubber plate 64. When the liquid breaks up into minuscule particles,solid contaminants entrained in the gas are encaptured, i.e., entrappedor dissolved by the liquid, thus collecting the solid particles from thegas. The solid thus entrapped and scrubbed from the polluted gas has tohave particle sizes considerably smaller than the openings in thedimples 74. Gaseous contaminants, such as carbon dioxide, can bedissolved in the liquid. Certain gaseous organic impurities such asphenols (as found in the waste gases from industrial processes) can bedissolved in various organic solvents. There is a great surface area ofliquid exposed to the contaminated gases and this will augment theabsorption of impurities from the gas as well as the entrainment ofsolid particles in the gas. The atomized liquid as well as the gaspasses over ramp 76 following the path of the arrows. As the substanceis directed downwardly by baffle '78 most of the entrapped contaminantstend to fall out or settle in well 80 while the remaining gas isdirected over bafile 82 towards Well 84 before finally escaping upexhaust stack 86. The entrapped contaminants are removed from wells 80and 84 by conduits 88 toward a disposal source (not shown).

Turning now to FIG. 5, the plate designated as 90 comprises a slightlydilferent method of channeling and directing liquid over the domes 92.Due to the design of the basin 96 around the base of the protrusions 92,the liquid being guided gravitationally down channel 94 tends to stayWithin the guide channels because of the wells 95 (FIG. 6). The liquidwhich tends to go around the protrusions will empty into the well 95thereby collecting and directing liquid to the next dome downstream.

FIG. 6 more clearly illustrates the particular design of the liquidchanneling. The multiple slots 98 in the domelike protrusions areparticularly effective in the gas cleaning operation previouslydescribed since the object is to pass as many solid contaminants throughthe apparatus for encapsulation by the liquid as possible. Theorientation of the slots 98 are designed so that their long axes are 90degrees to the liquid as the liquid moves over the dome radially fromthe apex of the dome 92.

FIG. 7 is an embodiment of the invention wherein the dimpled plate ortrough 100 is vertical or nearly so. A series of funnel-like catchbasins 102 collect and direct liquid over the dimples 104. By collectingthe liquid in this manner, the liquid flow rate can be controlled by thesize of the opening 106 at the exit of the diverging funnel 102.

FIG, 8 is a side view of the vertical spray apparatus, particularlyillustrating the depth of the liquid catching funnels 102 and theirrelationship to the domes 104.

Although particular embodiments have been chosen to best illustrate theadvantages of this invention, it is to be understood that the scope ofthe invention is not to be limited thereby.

I claim:

1. In a spray atomization device of the type that passes a thin layer ofliquid over the top of a curved surface and wherein a flow of a gaseousmedium under pressure is directed through an orifice on the curvedsurface to rupture the liquid layer spanning said orifice therebyatomizing said liquid, the improvement which comprises:

an inclined plate having a series of bulbous, discrete,

unconfined curved surfaces thereon, each discrete surface having atleast one orifice therein, extending outwardly from said plate,

channel means formed in said inclined plate leading to and extendingfrom succeeding ones of said discrete surfaces to direct the flow ofliquid from adjacent an upper portion of said plate so that liquid isguided over each of said discrete surfaces of the plate while traversingsaid plate toward a lower portion of the plate,

means to conduct gaseous fluid under pressure through said orifices insaid plate from the side of the plate opposite that containing theflowing liquid to atomize the liquid in a multiplicity of spraypatterns.

2. The invention of claim 1 wherein said liquid is combustible and isatomized in a multiplicity of spray patterns above said inclined plate,said atomized liquid being subsequently ignited to generate heatthereby.

'3. The invention of claim 1 wherein said liquid passes over saidinclined plate and a contaminated gas under pressure is conductedthrough said orifices in said plate whereby said contaminants entrainedin the gas is crap tured by the liquid and caused to settle out of thegas for removal therefrom prior to exhausting said gas into theatmosphere.

4. The invention of claim 1 wherein said bulbous surfaces on saidinclined plate are substantially aligned parallel along the slope ofsaid inclined plate.

5. The invention of claim 4, wherein said substantially aligned bulboussurfaces on said inclined plate are spaced between a first weir in saidplate located at the uppermost edge of said plate and a second catchbasin located at the lowermost edge of said plate whereby liquidoverflows said weir onto said plate and is collected in said basin atthe lowermost edge of said plate after said liquid traverses said plate,said collected liquid being recirculated by circulation means back tosaid weir.

6. The invention of claim 1 wherein liquid from a liquid supply sourceempties into a weir at the top edge of said plate, said liquid traversessaid plate gravitationally and is collected in a catch basin at thelowermost edge of said plate and wherein said liquid is circulated backto said liquid supply source by a circulation means.

7. In a spray atomization device of the type that passes a thin layer ofliquid over the top of a curved surface and wherein a flow of a gaseousmedium under pressure is directed through an orifice on the curvedsurface to rupture the liquid layer spanning said orifice therebyatomizing said liquid, the improvement which comprises:

an inclined plate having a series of discrete, curved surfaces, eachhaving at least one orifice therein, extending outwardly from saidplate, said inclined plate being enclosed by a structure forming atrough, the interior of the trough being formed by the underside of theplate and the inside walls of the structure, said interior cavityforming a manifold for conducting said gaseous medium under pressurethrough said orifices in said plate,

means to flow liquid from adjacent one portion of said plate so thatliquid flows over said discrete curved surfaces of the plate whiletraversing said plate toward another portion of the plate, and

means to conduct gaseous fluid under pressure through said orifices insaid plate from the opposite side of the plate to atomize the liquidabove said plate in a multiplicity of spray patterns.

8. In a spray atomization device of the type that passes a thin layer ofliquid over the top of a curved surface and wherein a flow of a gaseousmedium under pressure is directed through an orifice on the curvedsurface to rupture the liquid layer spanning said orifice therebyatomizing said liquid, the improvement which comprises:

an inclined plate having a series of discrete curved surfaces, eachhaving at least one orifice therein extending outwardly from said plate,wherein said outwardly extending curved surfaces on said inclined plateare substantially aligned parallel along the slope of said inclinedplate, each of said aligned curved surfaces of said plate are joined bya channel having tapering sides which converge from the base of saidcurved surface toward the next curved surface so as to concentrateliquid onto the surface of said next curved surface,

means to flow liquid from adjacent one portion of said plate so thatliquid flows over said discrete curved surfaces of the plate whiletraversing said plate toward another portion of the plate, and

means to conduct gaseous fluid under pressure through said orifices insaid plate from the opposite side of the plate to atomize the liquidabove said plate in a multiplicity of spray patterns.

9. In a spray atomization device of the type that passes a thin layer ofliquid over the top of a curved surface and wherein a flow of a gaseousmedium under pressure is directed through an orifice on the curvedsurface to rupture the liquid layer spanning said orifice therebyatomizing said liquid, the improvement which comprises:

a plate having a series of discrete curved surfaces, each having atleast one orifice therein extending outwardly from said plate andwherein multiple channels are provided in said plate between theoutwardly extending curved surfaces to direct liquid from one curvedsurface to the next,

means to flow liquid from adjacent one portion of said plate so thatliquid flows over said discrete curved surfaces of the plate whiletraversing said plate toward another portion of the plate, and

means to conduct gaseous fluid under pressure through said orifices insaid plate from the opposite side of the plate to atomize the liquidabove said plate in a multiplicity of spray patterns.

10. In a spray atomization device of the type that passes a thin layerof liquid over the top of a curved surface and wherein a flow of agaseous medium under pressure is directed through an orifice on thecurved surface to rupture the liquid layer spanning said orifice therebyatomizing said liquid, the improvement which comprises:

a plate having a series of discrete curved surfaces, each having atleast one orifice therein, extending outwardly from said plate, theplate being substantially vertical,

means to flow liquid from adjacent one portion of said plate so thatliquid flows over said discrete curved surfaces of the plate whiletraversing said plate toward another portion of the plate, whereby themeans to flow liquid over said curved surfaces in said plate includes aplurality of open-ended funnels attached to the plate and positionedabove and in line with each of said curved surfaces, said funnel havingits opened widest end on top and its opened narrow end at the bottomadjacent the base of said curved surface so as to direct liquid over thecurved surface, and

means to conduct gaseous fluid under pressure through said orifices insaid plate from the opposite side of 7 8 the plate to atomize the liquidabove said plate in a 3,425,059 1/1969 Babington 239-426X multiplicityof spray patterns. 3,504,859 4/ 1970 Babington et a1. 239-337XReferences Cited M. HENSON WOOD, JR., Primary Examiner UNITED STATESPATENTS 5 M. Y. MAR, Assistant Examiner 3,065,797 11/1962 Barnes 169153,421,692 1/1969 Babington et a1. 239426X 3,421,699 1/1969 Babington eta1. 239-426X 37, 426, 4 1

3,425,058 1/1969 Babington 239124 10

